Marine fuel vent

ABSTRACT

A marine fuel vent is used in connection with a boat hull and a marine fuel tank. The marine fuel vent comprises a nozzle with a bore through it, a cap at one end, a hose barb at the opposite end, and a threaded portion in between. The cap has a chamber and a wall with at least one hole through it. The cap hole includes a screen disposed in a counterbore. A cover engages the cap. A cover hole is aligned with the cap hole. A cup has a flange at one end, and a floor at the opposite end. The cup is mounted in the boat hull with the flange adjacent the hull outer surface. The nozzle is mounted in the cup with the cap inside the cup, and the threaded portion passing through a cup floor hole. The cup, cover, and screen are made from stainless steel. A bowl is mounted over the threaded portion and against the hull inner surface. The bowl has a shoulder at one end, and an annular groove on the outer surface, so that the bowl can be cut on the annular groove to shorten the bowl. The vent can thereby be installed on boat hulls of varying thickness. A nut engages the threaded portion. The nut has a flange at one end with an annular rim adapted to engage the bowl shoulder so as to center the bowl. The nozzle, bowl, and nut are made from either a thermoplastic or a thermoset resin.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

This invention relates to the field of fuel tank vents, and more particularly to a plastic vent with stainless steel portions, for use in connection with a marine fuel tank.

Marine fuel vents typically include a straight or elbow shaped nozzle made from stainless steel, or from bronze or zinc alloy with chrome plating. The nozzle is disposed inside the boat hull, and has a hose barb at one end for connection to the fuel tank. A cap portion is disposed outside the hull and is attached to the opposite end of the nozzle. Between the nozzle cap and nozzle hose barb is a threaded portion for a flange nut to secure the vent in the hull. The cap has one or more vent holes with stainless steel screens to block insects and arrest sparks. The cap can be the same metal as the nozzle, or it can be plastic. The main disadvantage of these metal alloys is their high cost. Further, they can corrode under certain conditions. The plastic is inexpensive, and does not corrode. However, the plastic is not as attractive as the chrome plated metal.

Marine fuel vents are available in two general types. The first type is mounted on the surface of the boat hull, and thus protrudes outward from the surface a significant distance. Only the nozzle penetrates the hull through a small hole. The second type is a flush vent, which is mounted in a larger hole than the surface type. A cup is set into the hole with only a thin flange seated against the outside of the hull. The vent cap is recessed in the cup. A bowl is installed behind the cup and seated against the inside of the hull. The flange nut bears against the bowl. The flush vent requires a longer threaded nozzle portion.

Accordingly, there is a need to provide a marine fuel vent that is made primarily of plastic for low cost, light weight, and corrosion-free construction.

There is a further need to provide a marine fuel vent of the type described and that has a stainless steel cap cover and cup for an attractive appearance.

There is a yet further need to provide a marine fuel vent of the type described which is flush mounted, and that will fit boats of different hull thickness while minimizing the length of the threaded nozzle portion.

There is a still further need to provide a marine fuel vent of the type described and that can be manufactured cost-effectively in large quantities of high quality.

BRIEF SUMMARY OF THE INVENTION

A marine fuel vent is used in connection with a boat hull, a marine fuel tank, and a hose communicating the vent with the tank. The boat hull has outer and inner surfaces, a predetermined thickness, and a mounting hole through it. The marine fuel vent comprises a nozzle extending between opposite proximal and distal ends. The nozzle has a bore through it, and a cap at the proximal end. The cap has a chamber communicating with the bore. The cap has a cap wall with at least one cap hole through it. The cap hole includes a counterbore with a screen disposed in the counterbore. The nozzle has a threaded portion adjacent the proximal end. The cap has a shoulder adjacent the threaded portion. The nozzle includes a hose barb at the distal end for attaching the hose.

A cover engages the cap. The cover has an interior, a wall, and at least one cover hole through the cover wall. The cover hole is aligned with the cap hole so as to communicate the cap chamber with the atmosphere.

A cup has a wall, a cavity, a flange attached to the cup wall at one end, and a floor attached to the cup wall at the opposite end. The floor has a hole through it adapted to receive the nozzle threaded portion. The cup, cover, and screen are made from stainless steel.

A bowl has a wall with outer and inner surfaces, and a cavity. The bowl has a shoulder at one end, and an annular groove on the outer surface, so that the bowl wall can be cut on the annular groove to shorten the bowl. Thus, the vent can be installed on a boat hull of greater than the predetermined thickness.

A nut engages the threaded portion. The nut has a flange at one end with an annular rim adapted to engage the bowl shoulder so as to center the bowl. The nozzle, bowl, and nut are made from either a thermoplastic or a thermoset resin.

Upon assembly, the cup is inserted into the hull mounting hole with the cup flange adjacent the boat hull outer surface. The nozzle threaded portion will pass through the cup floor hole. The cap will be disposed inside the cup cavity and the nozzle shoulder disposed adjacent the cup floor. The bowl will pass over the nozzle threaded portion until the bowl first end bears against the boat hull inner surface. The nut will engage the nozzle threaded portion, and the nut flange and rim will engage the bowl shoulder, thereby centering the bowl. The nut will be tightened, thereby clamping the vent to the boat hull. The hose will be connected between the vent and the tank, allowing fumes to vent safely.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

A more complete understanding of the present invention may be obtained from consideration of the following description in conjunction with the drawing, in which:

FIG. 1 is an exploded perspective assembly view of a marine fuel vent constructed in accordance with the invention.

FIG. 2 is a perspective view of the marine fuel vent of FIG. 1, showing the vent assembled on a boat hull.

FIG. 3 is a cross-sectional elevational view of the marine fuel vent of FIG. 1, taken along lines 3-3 of FIG. 2.

FIG. 4 is another cross-sectional elevational view of the marine fuel vent of FIG. 1, showing the vent assembled on a thicker boat hull with the bowl shortened.

FIG. 5 is a cross-sectional elevational view of another embodiment of the marine fuel vent, showing the vent with a straight nozzle assembled on a boat hull.

FIG. 6 is a front elevational view of a nozzle of the marine fuel vent of FIG. 1.

FIG. 7 is a right side view of the nozzle of FIG. 6.

FIG. 8 is a top view of the nozzle of FIG. 6.

FIG. 9 is a front cross-sectional elevational view of the nozzle of FIG. 6, taken along lines 9-9 of FIG. 8.

FIG. 10 is a perspective view of the nozzle of FIG. 6.

FIG. 11 is a another perspective view of the nozzle of FIG. 6.

FIG. 12 is a perspective view of a bowl of the marine fuel vent of FIG. 1.

FIG. 13 is a front elevational view of the bowl of FIG. 12.

FIG. 14 is a bottom view of the bowl of FIG. 12.

FIG. 15 is a front cross-sectional elevational view of the bowl of FIG. 12, taken along lines 15-15 of FIG. 14.

FIG. 16 is a perspective view of a cup of the marine fuel vent of FIG. 1.

FIG. 17 is a front elevational view of the cup of FIG. 16.

FIG. 18 is a bottom view of the cup of FIG. 16.

FIG. 19 is a front cross-sectional elevational view of the cup of FIG. 16, taken along lines 19-19 of FIG. 18.

FIG. 20 is a perspective view of a cover of the marine fuel vent of FIG. 1.

FIG. 21 is a front elevational view of the cover of FIG. 20.

FIG. 22 is a bottom view of the cover of FIG. 20.

FIG. 23 is a front cross-sectional elevational view of the cover of FIG. 20, taken along lines 23-23 of FIG. 22.

FIG. 24 is a perspective view of a nut of the marine fuel vent of FIG. 1.

FIG. 25 is a front elevational view of the nut of FIG. 24.

FIG. 26 is a bottom view of the nut of FIG. 24.

FIG. 27 is a front cross-sectional elevational view of the nut of FIG. 24, taken along lines 27-27 of FIG. 26.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawing, a marine fuel vent is shown at 30, and is for use in connection with a boat hull 32, a marine fuel tank (not shown), and a hose (not shown) communicating the vent 30 with the tank. The boat hull 32 has an outer surface 34 and an inner surface 36. The boat hull 32 is of a predetermined thickness and has a mounting hole 38 therethrough. The marine fuel vent 30 comprises a nozzle 40 extending between opposite proximal 42 and distal 44 ends. The nozzle 40 is an elbow, with the proximal end 42 at a substantially right angle to the distal end 44.

The nozzle 40 has a central axis and a bore 46 therethrough from the proximal end 42 to the distal end 44. The nozzle 40 has a cap 48 at the proximal end 42. The cap 48 has a chamber 50 communicating with the bore 46. The cap 48 has a cap wall 52 and at least one, and preferably several, cap holes 54 through the cap wall 52. Each cap hole 54 has a counterbore 56. The nozzle 40 has a threaded portion 58 on the central axis adjacent the proximal end 42. The cap 48 has a shoulder 60 adjacent the threaded portion 58. The nozzle 40 has attaching means, typically a hose barb 62, at the distal end 44 of the nozzle 40 for attaching the hose to the nozzle 40. At least one screen 55 is adapted for placement in each counterbore 56, and is disposed in each counterbore 56.

A cover 64 has an interior 66 adapted for closely engaging the cap 48. The cover 64 has a cover wall 68 and at least one, and preferably several, cover holes 70 through the cover wall 68. The cover 64 is juxtaposed over the cap 48. Each cover hole 70 is aligned with one of the cap holes 54 so as to communicate the cap chamber 50 with the atmosphere.

A cup 72 has a cup wall 74 extending between opposite first 76 and second 78 ends. The cup 72 has an cavity 80 extending between the first 76 and second 78 ends. The cup 72 has a flange 82 attached to the cup wall 74 at the first end 76. The cup 72 has a floor 84 attached to the cup wall 74 at the second end 78. The floor 84 has a floor hole 86 therethrough adapted to receive the nozzle threaded portion 58. The cup 72, cover 64, and screen 55 are made from a metal selected from the group consisting of stainless steel, brass, bronze, monel, and aluminum. They preferably are made from stainless steel, and polished for an attractive appearance.

A bowl 88 has a bowl wall 90 extending between opposite first 92 and second 94 ends. The bowl wall 90 has outer 96 and inner 98 surfaces. The bowl 88 includes a cavity 100 extending between the first 92 and second 94 ends. The bowl 88 has a shoulder 102 at the second end 94. The bowl 88 has an annular groove 104 on the bowl wall outer surface 96. This is so that the bowl wall 90 can be cut on the annular groove 104 to shorten the bowl 88 and thereby enable installation of the vent 30 on a boat hull 32 of greater than the predetermined thickness.

A nut 106 is adapted to engage the threaded portion 58. The nut 106 has a flange 108 at one end. The flange 108 has an annular rim 110 adapted to engage the bowl shoulder 102 so as to substantially center the bowl 88 on the central axis. The nozzle 40, bowl 88, and nut 106 are made from a polymer selected from the group consisting of thermoplastic resins and thermoset resins.

An outer gasket 112 is disposed between the cup flange 82 and the hull outer surface 34. An inner gasket 114 is disposed between the cup floor 84 and the cap shoulder 60. The inner 114 and outer 112 gaskets are made from an elastomer.

Upon assembly, the cup 72 will be inserted into the hull mounting hole 38 with the cup flange 82 adjacent the boat hull outer surface 34. The nozzle threaded portion 58 will pass through the cup floor hole 86. The cap 48 will be disposed inside the cup cavity 80 and the cap shoulder 60 disposed adjacent the cup floor 84. The bowl 88 will pass over the nozzle threaded portion 58. The bowl first end 92 will bear against the boat hull inner surface 36. The nut 106 will engage the nozzle threaded portion 58, and the nut flange 108 and annular rim 110 will engage the bowl shoulder 102, thereby centering the bowl 88 on the central axis. The nut 106 will be tightened, thereby clamping the vent 30 to the boat hull 32. The hose will then be connected between the vent and the tank, thereby communicating the tank with the atmosphere, and allowing fumes to vent safely.

Referring now to FIG. 4, the marine fuel vent 30, described above, is shown attached to boat hull 132, which is of a predetermined thickness greater than that of boat hull 32. The bowl wall 90 has been cut on the annular groove 104 to shorten the bowl 88. This accommodates the thicker hull 132 without the need for a longer nozzle threaded portion 58.

Turning now to FIG. 5, another embodiment of the marine fuel vent constructed in accordance with the invention is shown at 230. Marine fuel vent 230 is similar to marine fuel vent 30 described above in that it is for use in connection with a boat hull 232, a marine fuel tank, and a hose communicating the vent 230 with the tank. The boat hull 232 is of a predetermined thickness and has a mounting hole 238 therethrough. The marine fuel vent 230 comprises a nozzle 240 with a central axis and a bore 246 therethrough. The nozzle 240 has a cap 248 with a plurality of cap holes 254. Each cap hole 254 has a counterbore 256. A screen 255 is disposed in each counterbore 256. The nozzle 240 has a threaded portion 258 and a hose barb 262.

A cover 264 is juxtaposed over the cap 248 and has a plurality of cover holes 270. Each cover hole 270 is aligned with one of the cap holes 254.

A cup 272 has a flange 282 and a floor 284. The floor 284 has a floor hole 286 therethrough adapted to receive the nozzle threaded portion 258. The cup 272, cover 264, and screen 255 are made from stainless steel, and polished for an attractive appearance.

A bowl 288 has a shoulder 302 and an annular groove 304.

A nut 306 is adapted to engage the threaded portion 258. The nut 306 has a flange 308 at one end with an annular rim 310 adapted to engage the bowl shoulder 302. The nozzle 240, bowl 288, and nut 306 are made from a thermoplastic or thermoset resin.

An outer gasket 312 is disposed between the cup flange 282 and the hull outer surface 234. An inner gasket 314 is disposed between the cup floor 284 and the cap shoulder 260. The inner 314 and outer 312 gaskets are made from an elastomer.

Marine fuel vent 230 differs from marine fuel vent 30 described above in that the nozzle 240 is substantially straight.

Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications that will come within the scope of the appended claims is reserved.

PARTS LIST MARINE FUEL VENT PART NO. DESCRIPTION 30 marine fuel vent (elbow) 32 boat hull 34 boat hull outer surface 36 boat hull inner surface 38 mounting hole 40 nozzle 42 nozzle proximal end 44 nozzle distal end 46 nozzle bore 48 cap 50 cap chamber 52 cap wall 54 cap hole 55 screen 56 counterbore 58 threaded portion 60 shoulder 62 hose barb 64 cover 66 cover interior 68 cover wall 70 cover hole 72 cup 74 cup wall 76 cup first end 78 cup second end 80 cup cavity 82 cup flange 84 cup floor 86 floor hole 88 bowl 90 bowl wall 92 first end 94 second end 96 outer surface 98 inner surface 100 bowl cavity 102 bowl shoulder 104 annular groove 106 nut 108 flange 110 annular rim 112 outer gasket 114 inner gasket 132 boat hull (thicker) 230 marine fuel vent (straight) 232 boat hull 234 boat hull outer surface 236 boat hull inner surface 238 mounting hole 240 nozzle 242 nozzle proximal end 244 nozzle distal end 246 nozzle bore 248 cap 250 cap chamber 252 cap wall 254 cap hole 255 screen 256 counterbore 258 threaded portion 260 shoulder 262 hose barb 264 cover 266 cover interior 268 cover wall 720 cover hole 272 cup 274 cup wall 276 cup first end 278 cup second end 280 cup cavity 282 cup flange 284 cup floor 286 floor hole 288 bowl 290 bowl wall 292 first end 294 second end 296 outer surface 298 inner surface 300 bowl cavity 302 bowl shoulder 304 annular groove 306 nut 308 flange 310 annular rim 312 outer gasket 314 inner gasket 

1. A marine fuel vent for use in connection with a boat hull, a marine fuel tank, and a hose communicating the vent with the tank, the boat hull having an outer surface and an inner surface, the boat hull being of a predetermined thickness and having a mounting hole therethrough, the marine fuel vent comprising: a nozzle extending between opposite proximal and distal ends, the nozzle having a central axis, the nozzle having a bore therethrough from the proximal end to the distal end, the nozzle having a cap at the proximal end, the cap having a chamber communicating with the bore, the cap having a cap wall and at least one cap hole through the cap wall, the cap hole having a counterbore, the nozzle having a threaded portion on the central axis adjacent the proximal end, the cap having a shoulder adjacent the threaded portion, the nozzle having attaching means at the distal end for attaching the hose to the nozzle; at least one screen, the screen being adapted for placement in the counterbore; a cover having an interior adapted for closely engaging the cap, the cover having a cover wall and at least one cover hole through the cover wall; a cup having a cup wall extending between opposite first and second ends, the cup having a cup cavity extending between the first and second ends, the cup having a flange attached to the cup wall at the first end, the cup having a floor attached to the cup wall at the second end, the floor having a floor hole therethrough adapted to receive the nozzle threaded portion; a bowl having a bowl wall extending between opposite first and second ends, the bowl wall having outer and inner surfaces, the bowl having a bowl cavity extending between the first and second ends, the bowl having a shoulder at the second end; and a nut adapted to engage the threaded portion, the nut having a flange at one end, the flange having an annular rim adapted to engage the bowl shoulder so as to substantially center the bowl on the central axis; so that upon assembly, the screen will be inserted into the counterbore, the cover will be juxtaposed over the cap, the cover hole will be aligned with the cap hole so as to communicate the cap chamber with the atmosphere, the cup will be inserted into the hull mounting hole with the cup flange adjacent the boat hull outer surface, the nozzle threaded portion will pass through the cup floor hole, the cap will be disposed inside the cup cavity and the nozzle shoulder disposed adjacent the cup floor, the bowl will pass over the nozzle threaded portion, the bowl first end will bear against the boat hull inner surface, the nut will engage the nozzle threaded portion, the nut flange and rim will engage the bowl shoulder, thereby centering the bowl on the central axis, the nut will be tightened, thereby clamping the vent to the boat hull, the hose will be connected between the vent and the tank, thereby communicating the tank with the atmosphere, and allowing fumes to vent safely.
 2. The marine fuel vent of claim 1, wherein the bowl further comprises an annular groove on the bowl wall outer surface, so that the bowl wall can be cut on the annular groove to shorten the bowl and thereby enable installation of the vent on a boat hull of greater than the predetermined thickness.
 3. The marine fuel vent of claim 1, wherein: the nozzle, bowl, and nut are made from a polymer selected from the group consisting of thermoplastic resins and thermoset resins; the cup, cover, and screen are made from a metal selected from the group consisting of stainless steel, brass, bronze, monel, and aluminum.
 4. The marine fuel vent of claim 1, wherein the attaching means further comprises a hose barb at the distal end of the nozzle for attaching the hose.
 5. The marine fuel vent of claim 1, further comprising: an outer gasket disposed between the cup flange and the hull outer surface; and an inner gasket disposed between the cup floor and the cap shoulder; the inner and outer gaskets being made from an elastomer.
 6. The marine fuel vent of claim 1, wherein the nozzle is substantially straight from the proximal end to the distal end.
 7. The marine fuel vent of claim 1, wherein the nozzle is an elbow, with the proximal end at a substantially right angle to the distal end.
 8. A marine fuel vent for use in connection with a boat hull, a marine fuel tank, and a hose communicating the vent with the tank, the boat hull having an outer surface and an inner surface, the boat hull being of a predetermined thickness and having a mounting hole therethrough, the marine fuel vent comprising: a nozzle extending between opposite proximal and distal ends, the nozzle having a central axis, the nozzle having a bore therethrough from the proximal end to the distal end, the nozzle having a cap at the proximal end, the cap having a chamber communicating with the bore, the cap having a cap wall and at least one cap hole through the cap wall, the cap hole having a counterbore, the nozzle having a threaded portion on the central axis adjacent the proximal end, the cap having a shoulder adjacent the threaded portion, the nozzle having attaching means at the distal end for attaching the hose to the nozzle; at least one screen, the screen being adapted for placement in the counterbore; a cover having an interior adapted for closely engaging the cap, the cover having a cover wall and at least one cover hole through the cover wall; a cup having a cup wall extending between opposite first and second ends, the cup having a cup cavity extending between the first and second ends, the cup having a flange attached to the cup wall at the first end, the cup having a floor attached to the cup wall at the second end, the floor having a floor hole therethrough adapted to receive the nozzle threaded portion; the cup, cover, and screen being made from a metal selected from the group consisting of stainless steel, brass, bronze, monel, and aluminum; a bowl having a bowl wall extending between opposite first and second ends, the bowl wall having outer and inner surfaces, the bowl having a bowl cavity extending between the first and second ends, the bowl having a shoulder at the second end; a nut adapted to engage the threaded portion, the nut having a flange at one end, the flange having an annular rim adapted to engage the bowl shoulder so as to substantially center the bowl on the central axis; and the nozzle, bowl, and nut being made from a polymer selected from the group consisting of thermoplastic resins and thermoset resins; so that upon assembly, the screen will be inserted in the counterbore, the cover will be juxtaposed over the cap, the cover hole will be aligned with the cap hole so as to communicate the cap chamber with the atmosphere, the cup will be inserted into the hull mounting hole with the cup flange adjacent the boat hull outer surface, the nozzle threaded portion will pass through the cup floor hole, the cap will be disposed inside the cup cavity and the nozzle shoulder disposed adjacent the cup floor, the bowl will pass over the nozzle threaded portion, the bowl first end will bear against the boat hull inner surface, the nut will engage the nozzle threaded portion, the nut flange and rim will engage the bowl shoulder, thereby centering the bowl on the central axis, the nut will be tightened, thereby clamping the vent to the boat hull, the hose will be connected between the vent and the tank, thereby communicating the tank with the atmosphere, and allowing fumes to vent safely.
 9. The marine fuel vent of claim 8, wherein the bowl further comprises an annular groove on the bowl wall outer surface, so that the bowl wall can be cut on the annular groove to shorten the bowl and thereby enable installation of the vent on a boat hull of greater than the predetermined thickness.
 10. The marine fuel vent of claim 8, wherein the attaching means further comprises a hose barb at the distal end of the nozzle for attaching the hose.
 11. The marine fuel vent of claim 8, further comprising: an outer gasket disposed between the cup flange and the hull outer surface; and an inner gasket disposed between the cup floor and the cap shoulder; the inner and outer gaskets being made from an elastomer.
 12. The marine fuel vent of claim 8, wherein the nozzle is substantially straight from the proximal end to the distal end.
 13. The marine fuel vent of claim 8, wherein the nozzle is an elbow, with the proximal end at a substantially right angle to the distal end.
 14. A marine fuel vent for use in connection with a boat hull, a marine fuel tank, and a hose communicating the vent with the tank, the boat hull having an outer surface and an inner surface, the boat hull being of a predetermined thickness and having a mounting hole therethrough, the marine fuel vent comprising: a nozzle extending between opposite proximal and distal ends, the nozzle having a central axis, the nozzle having a bore therethrough from the proximal end to the distal end, the nozzle having a cap at the proximal end, the cap having a chamber communicating with the bore, the cap having a cap wall and at least one cap hole through the cap wall, the cap hole having a counterbore, the nozzle having a threaded portion on the central axis adjacent the proximal end, the cap having a shoulder adjacent the threaded portion, the nozzle having a hose barb at the distal end of the nozzle for attaching the hose to the nozzle; at least one screen, the screen being disposed in the counterbore; a cover having an interior adapted for closely engaging the cap, the cover having a cover wall and at least one cover hole through the cover wall, the cover being juxtaposed over the cap, the cover hole being aligned with the cap hole so as to communicate the cap chamber with the atmosphere; a cup having a cup wall extending between opposite first and second ends, the cup having a cup cavity extending between the first and second ends, the cup having a flange attached to the cup wall at the first end, the cup having a floor attached to the cup wall at the second end, the floor having a floor hole therethrough adapted to receive the nozzle threaded portion; the cup, cover, and screen being made from stainless steel; a bowl having a bowl wall extending between opposite first and second ends, the bowl wall having outer and inner surfaces, the bowl having a bowl cavity extending between the first and second ends, the bowl having a shoulder at the second end, the bowl having an annular groove on the bowl wall outer surface, so that the bowl wall can be cut on the annular groove to shorten the bowl and thereby enable installation of the vent on a boat hull of greater than the predetermined thickness; a nut adapted to engage the threaded portion, the nut having a flange at one end, the flange having an annular rim adapted to engage the bowl shoulder so as to substantially center the bowl on the central axis; and the nozzle, bowl, and nut being made from a polymer selected from the group consisting of thermoplastic resins and thermoset resins; so that upon assembly, the cup will be inserted into the hull mounting hole with the cup flange adjacent the boat hull outer surface, the nozzle threaded portion will pass through the cup floor hole, the cap will be disposed inside the cup cavity and the nozzle shoulder disposed adjacent the cup floor, the bowl will pass over the nozzle threaded portion, the bowl first end will bear against the boat hull inner surface, the nut will engage the nozzle threaded portion, the nut flange and rim will engage the bowl shoulder, thereby centering the bowl on the central axis, the nut will be tightened, thereby clamping the vent to the boat hull, the hose will be connected between the vent and the tank, thereby communicating the tank with the atmosphere, and allowing fumes to vent safely.
 15. The marine fuel vent of claim 14, further comprising: an outer gasket disposed between the cup flange and the hull outer surface; and an inner gasket disposed between the cup floor and the cap shoulder; the inner and outer gaskets being made from an elastomer.
 16. The marine fuel vent of claim 14, wherein the nozzle is substantially straight from the proximal end to the distal end.
 17. The marine fuel vent of claim 14, wherein the nozzle is an elbow, with the proximal end at a substantially right angle to the distal end. 